1. Field of the Invention
The present invention relates to a display substrate having a thin film transistor (“TFT”).
2. Description of the Related Art
A display substrate that serves as an array substrate for a display apparatus, in general, includes a substrate, a plurality of thin film transistors (“TFTs”) arranged on the substrate, and a plurality of pixel electrodes electrically connected to the TFTs in one-to-one correspondence.
In order to switch a data signal applied to the pixel electrodes, the TFTs include a semiconductor material that serves as a conductor under certain conditions. Silicon material has been widely used as the semiconductor material. In addition, an organic semiconductor material and an oxide semiconductor material have also been used as the semiconductor material.
In general, the oxide semiconductor material has a superior electrical mobility, thereby improving switching characteristics of the TFT. However, the switching characteristics of the TFT are changed according to the mixture ratio of each element in the oxide semiconductor material.